Preparation Steps

• Line the base of a 9-inch springform pan with parchment and lightly grease the sides. Chill a large mixing bowl and whisk/beaters for 10 minutes.
• Make the crust: Pulse 30 Oreo cookies in a food processor to fine crumbs. Add melted butter and sea salt; pulse again until the crumbs are evenly moistened. Press firmly into the bottom and halfway up the sides of the pan. Freeze for 15 minutes to set while you make the filling.
• Melt the chocolate: Set a heatproof bowl over a pot of barely simmering water (do not let the bowl touch the water). Add the chopped dark chocolate and espresso powder; stir until smooth. Remove from heat and cool until just warm to the touch.
• Beat the cream cheese, granulated sugar, cocoa powder, and vanilla in a separate bowl on medium speed until completely smooth and fluffy, 2 to 3 minutes. Scrape the bowl. With the mixer on low, stream in the cooled melted chocolate and beat until fully combined and glossy.
• In the chilled bowl, whip 1 cup cold heavy cream with 2 tablespoons powdered sugar to medium-firm peaks. Fold the whipped cream into the chocolate cream cheese in two additions until no streaks remain.
• Fold in the 16 crushed Oreos. Spoon the filling into the cold crust, smooth the top, and tap the pan gently on the counter to release air bubbles. Cover and refrigerate at least 4 to 6 hours, or overnight for clean slices.
• For the topping (make ahead while the cheesecake chills): Using the same chilled bowl, whip 3/4 cup heavy cream, 3 tablespoons powdered sugar, and 1/2 teaspoon vanilla to stiff peaks. Transfer to a piping bag fitted with a large round or star tip; refrigerate until serving.
• To finish: Run a thin warm knife around the inside edge of the pan and release the springform ring. Pipe swirls of whipped cream around the cheesecake and garnish with additional Oreos and chocolate curls, if using. Slice with a hot, dry knife for neat edges.